new bff hillary clinton and meryl streep. bill clinton and led zeppelin. ♪ hey, hey, mama ♪ gone make the you sweat gonna make you move ♪ >> reporter: everyone rocked as foo fighters, kid rock and lenny kravitz belted out some of zeppelin's greatest hits. ♪ i'm gonna give you my love >> reporter: and it took a bevy of famous comedians to pay tribute to their lee, late-night comedian david letterman. >> was he a brilliant, subtle, passive-aggressive, successful parody of talk show host? or some midwestern goon who was a little bit off? [ laughter ] >> when i was a teenager, dave was my justin bieber. [ laughter ] and i like to think of myself as his selena gomez. >> reporter: but it was ray romano who was able to hit the emotional highlight of the evening as he celebrated his notoriously shy friend and mentor. >> what johnny carson was for you, you are for the rest of all of us here. and i don't want to get schmaltzy. i'm not good at that. i know you're not good, but you know what, the hell with it. my father passed aw